Article of footwear with modifiable sole

ABSTRACT

An article of footwear is provided with a modifiable sole having raised projections and/or drain guides. The raised projections are capable of receiving a threaded screw to increase the traction between the sole and an underlying ground surface. Information-conveying indicial markings can be provided on the base surface and associated with the raised projections, the indicial markings conveying information regarding the type of threaded screw that can be received by the raised projections and where to attach a threaded screw to the sole. The drain guides indicate where drain holes can be formed in the sole to enhance drainage

BACKGROUND OF THE INVENTION

The present invention relates to footwear, and more particularly to a sole for an article of footwear.

Conventional articles of footwear include an upper and a sole secured to a lower surface of the upper. The upper provides a void that receives a person's foot and positions the foot with respect to the sole. The sole may provide traction or cushion for the foot under a variety of conditions, e.g., walking, running or standing, or a combination thereof, and commonly includes a midsole and an outsole. A footbed or insole typically is disposed in the interior of the upper for additional cushion.

The general function of the sole is to provide a layer of protection for the wearer's foot. The sole can be designed not only to protect the foot from contact with the ground, but also to provide improved comfort and support for the foot. There is an ongoing effort to develop new and improved sole constructions that provide optimal performance across various applications. To provide enhanced grip, it is common to incorporate lugs or treads into the ground-contacting surface of the sole. Conventional lug constructions can suffer from a number of typical problems, including that lugs are often not designed for multi-surface or multi-condition use. Devices for enhancing traction are known, such as spikes or cleats, which can be added to footwear. Some footwear includes threaded bores for traction devices, providing the ability to add or remove spike and cleats depending on conditions. Such bores can collect dirt and mud when traction devices are not attached.

Users have also taken a do-it-yourself approach to modifying footwear, including adding traction devices to footwear not originally designed to accommodate traction devices. One approach includes drilling screws into the sole for enhanced traction. Similarly, users have added drain holes to footwear not originally designed to accommodate drainage. Because such footwear is not configured for the addition of screws or drain holes, users must take a trial-and-error approach in the placement of screws and drain holes, often damaging the footwear in the process.

Despite continuing efforts, there remains a need for a sole that can be modified to suit a wearer's needs, including providing optimal performance across various conditions and terrains.

SUMMARY OF THE INVENTION

The present invention provides an article of footwear having an upper and a sole joined with the upper. The sole includes a base surface and a plurality of guard lugs extending from the base surface. Each guard lug has a distal end forming at least a portion of a ground-engaging surface of the sole. The sole further includes a plurality of raised projections that can receive a threaded screw to increase the traction between the sole and an underlying ground surface. Each raised projection extends from the base surface to a screw-receiving surface adapted to confront a screw head of the threaded screw. The sole further includes information-conveying indicial markings provided on the base surface and associated with the plurality of raised projections, the indicial markings conveying information regarding the type of threaded screw that can be received by the plurality of raised projections and where to attach a threaded screw to the sole.

In one embodiment, the guard lugs have a lug height defined by the distance between the base surface and the distal end and the projections have a projection height defined by the distance between the base surface and the screw-receiving surface, and the projection height is less than the lug height. In certain embodiments, the guard lugs project farther from the base surface than the indicial markings.

In one embodiment, the indicial markings include one or more letters, numbers, and/or symbols on the base surface. In certain embodiments, the indicial markings are raised elements molded on the base surface.

In one embodiment, the raised projections include pilot holes disposed on the screw-receiving surface thereof, the pilot holes acting as a guide for insertion of a threaded screw. In certain embodiments, the screw-receiving surfaces further include an X-shaped formation, with the pilot holes disposed at a center of each of the X-shaped formations.

In one embodiment, the sole includes multiple drain guides indicating where drain holes can be formed in the sole to enhance drainage. The drain guides can include a raised rim extending from the base surface and a drillable surface disposed within a boundary defined by the raised rim. In certain embodiments, the sole includes information-conveying indicial markings associated with the plurality of drain guides, the indicial markings conveying information regarding how to modify the sole for enhanced drainage.

In some embodiments, the sole has a forefoot region, an arch region, and a heel region, with the guard lugs and raised projections disposed in the forefoot and heel regions, and drain guides formed in the forefoot region.

In one embodiment, the raised projections are non-threaded, and the screw-receiving surfaces comprise closed ground-facing surfaces.

In one embodiment, the article of footwear includes at least one screw having a threaded shaft and a head. The screw is receivable on one of the plurality of raised projections, with the head of the screw meeting the screw-receiving surface.

In one embodiment, the base surface can be bounded by a peripheral edge comprising a medial edge, a lateral edge, a toe edge, and a heel edge. The raised projections can include medial projections provided along the medial edge and lateral projections provided along the lateral edge, with the medial and lateral projections longitudinally offset from each other with respect to a direction generally extending along the length of the footwear between the toe edge, and a heel edge.

In one embodiment, the sole comprises an outsole and a midsole positioned between the upper and the outsole, the outsole comprising the base surface.

In one embodiment, the raised projections are nested with guard lugs. The guard lugs can be chevron-shaped, and have a first V-shaped surface defining an outer vertex and a second V-shaped surface defining an inner vertex. Each of the raised projections can be nested in the second V-shaped surface of one of the plurality of guard lugs.

In another embodiment, the present invention provides a sole for an article of footwear. The sole includes a midsole and an outsole joined to the midsole. The outsole includes a base surface, a plurality of guard lugs extending from the base surface, and a plurality of raised projections capable of receiving a threaded screw to increase the traction between the sole and the underlying ground surface. Information-conveying indicial markings can be provided on the base surface and associated with the plurality of raised projections, the indicial markings conveying information regarding the type of threaded screw that can be received by the raised projections and where to attach a threaded screw to the sole.

The present invention provides an article of footwear that combines a high degree of customization with conveniently modifiable sole. By providing dedication locations for adding screws or drain holes, accompanied by indicial markings, a user can confidently customize the footwear for a variety of terrains and conditions.

These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.

Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a bottom perspective view of an article of footwear having a sole in accordance with an embodiment of the present invention.

FIG. 1B is a view similar to FIG. 1A, showing the sole modified with screws and drain holes.

FIG. 2 is a bottom plan view of the sole from FIG. 1.

FIG. 3 is an enlarged view of a forefoot section of the sole from FIG. 2.

FIG. 4 is an enlarged view of a heel section of the sole from FIG. 2.

FIG. 5 is an enlarged bottom plan view of a screw-receiving projection of the sole from FIG. 2.

FIG. 6 is a side view of the screw-receiving projection from FIG. 5.

FIG. 7 is a cross-sectional view of the screw-receiving projection from FIG. 5.

FIG. 8 is a perspective view of one embodiment of a screw that can be installed on the screw-receiving projection.

FIG. 9A is a sectional view of the sole, taken through line IX-IX of FIG. 2.

FIG. 9B is a view similar to FIG. 9A, with a screw installed in a screw-receiving projection.

FIG. 10 is a sectional view of the sole, taken through line X-X of FIG. 2.

FIG. 11 is an enlarged bottom plan view of a portion of the sole, showing indicial markings for conveying information regarding how to adapt the sole for enhanced traction and/or drainage.

FIG. 12 is a sectional view of the sole, taken through line XII-XII of FIG. 2.

DESCRIPTION OF THE CURRENT EMBODIMENT

An article of footwear in accordance with an embodiment of the present invention is shown in FIG. 1A, and generally designated 10. Generally, the footwear 10 includes an upper 12 and a sole 14 joined with the upper 12. The upper 12 defines a void or chamber for receiving person's foot and positioning the foot with respect to the sole 14. The sole 14 includes a ground-engaging surface 16 defining the bottom of the footwear 10 and can include lugs, tread, or other gripping features designed to enhance traction between the footwear 10 and an underlying ground surface. To further enhance traction, such as for icy conditions, the sole 14 can include raised projections 18 that are capable of receiving a threaded screw 20, as shown in FIG. 1B, to increase the traction between the sole 14 and the underlying ground surface. Indicial markings 22 can be provided on the sole 14 to convey information regarding how to modify the sole for enhanced traction, including information such as where to place screws 20 on the sole 14 for optimal performance and what type of screws 20 should be used. To optionally adapt the footwear for increased drainage, the sole 14 can include drain guides 24 where drain holes 26, as shown in FIG. 1B can be added to the sole 14. Indicial markings 28 can be provided on the sole 14 to convey information regarding how to modify the sole 14 for enhanced drainage, including information such as where to drill drain holes 26 on the sole 14 for optimal drainage and what type of drill bit should be used.

The footwear 10 can be produced and sold to a consumer as shown in FIG. 1A, i.e. free of any screws 20 or drain holes 26. The user can modify the footwear 10 to add one or more screws 20 and/or drain holes 26 as the terrain and conditions warrant. FIG. 1B shows screws 20 added to each of the projections 18 and drain holes 26 formed in each drain guide 24. It is understood, however, that the footwear 10 can be customized with any number of screws 20 and drain holes 26 using any subset or combination of projections 18 and drain guides 24 on the sole 14.

A sole 14 in accordance with the present invention may be joined to essentially any type of footwear upper capable of being joined to a sole. Although the current embodiment of footwear 10 is illustrated in the context of a trail shoe, it may be incorporated into any type or style of footwear, including casual shoes, trail boots, hiking boots, work boots, all-terrain shoes, barefoot running shoes, athletic shoes, running shoes, performance shoes, sneakers, conventional tennis shoes, walking shoes, multisport footwear, boots, dress shoes or any other type of footwear or footwear components.

Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer”, “outwardly,” “below” and “above” are used to assist in describing the embodiments based on the orientation of the embodiments shown in the illustrations. Further, the terms “medial,” “lateral” and “longitudinal” are used in the manner commonly used in connection with footwear. For example, when used in referring to a side of the footwear, the term “medial” refers to the inward side (that is, the side facing the other shoe) and “lateral” refers to the outward side. When used in referring to a direction, the term “longitudinal direction” refers to a direction generally extending along the length of the footwear between toe and heel, and the term “lateral direction” refers to a direction generally extending across the width of the footwear between the medial and lateral sides of the footwear. The use of directional terms should not be interpreted to limit the invention to any specific orientation.

Additionally, as used herein, the term “arch section” (or midfoot section or arch) refers generally to the portion of the footwear or sole corresponding to the arch or midfoot of the wearer's foot; the term “forefoot section” (or forefoot) refers generally to the portion of the footwear forward of the arch section corresponding to the forefoot (for example, including the ball and the toes) of a wearer's foot; and the term “heel section” (or heel) refers generally to that portion of the footwear rearward of the arch section corresponding to the heel of the wearer's foot. For example, the sole 14 can include a forefoot section 30, an arch or midfoot section 32 and a heel section 34, generally identified in FIG. 2. Delineation of these regions 30-34 may vary depending upon the configuration of the sole 14 and/or footwear 10.

The sole 14 may be joined to the upper 12 using essentially any type of footwear construction, such as a cemented construction, a direct-attach construction (e.g. direct injection molding), a Strobel-stitched construction, a stitchdown construction, a McKay stich construction, a California construction, a force-lasted construction, a slip-lasted construction, a moccasin construction, a direct vulcanizing construction or a welted construction (e.g. Goodyear welt or Blake welt). The upper 12 may be configured to implement the desired footwear construction. For example, the bottom of the upper 12 may be closed with a Strobel-board to implement a Strobel-stitched construction or with an insole board to implement a direct-attached or welted construction.

Optionally, although not shown, the footwear 10 can be constructed to include a knitted upper 12, constructed for example by weaving or knitting techniques, such as circular knitting, flat knitting, Jacquard knitting or other types of knitting. The joining of the sole 14 and the knitted upper 12 can be accomplished using adhesives, cement, injection molding, pour molding, or any other technique used to join a knitted upper and sole. Of course, the footwear 10 can be provided with any other type or style of upper construction capable of being suitably joined with the sole 14.

The sole 14 generally includes a midsole 36 and an outsole 38. The midsole 36 is positioned between the upper 12 and the outsole 38, and is used to provide cushioning, fit, comfort, and support. In the embodiment shown, the outsole 38 defines the ground-engaging surface 16 and provides grip and traction. The midsole 36 and outsole 38 each have a corresponding forefoot portion, arch region or mid-foot portion, and heel portion within the forefoot section 30, arch or midfoot section 32 and heel section 34 of the sole 14.

The midsole 36 can be constructed from a material having a first density that is generally less dense than the density of the material from which the outsole 38 is constructed. The first density of the midsole 36 can be such that it compresses relatively easily to provide cushion to the wearer's foot. The midsole 36 can be constructed from ethylene-vinyl acetate (EVA), polyurethane, latex, foam, a gel, or other materials, including, but not limited to, EVA foam or polyurethane foam, or any of the other materials as described below and suitable for additive manufacturing processes.

The outsole 38 can be disposed below the midsole 36 and the upper 12. The outsole 38 can be adhered, cemented, and/or molded directly to a lower surface of the midsole 36 in the regions where these elements contact one another to form the sole 14. In the some embodiments, the outsole 38 can be manufactured from a single, one-piece layer that extends over portions of the midsole 36. In other embodiments, the outsole 38 can be manufactured from a plurality of discrete segments that are separately secured to the undersurface of the midsole 12.

The outsole 38 can be constructed from one or more materials, such as rubber. Alternatively, the outsole 38 can be constructed from polyurethane (PU), thermoplastic polyurethane elastomer (TPU), ethylene-vinyl acetate (EVA), synthetic rubber, nylon, or other polymer blends that include nylon, PU, TPU, and/or EVA. These materials are merely exemplary, and the outsole 38 can be constructed from essentially any relatively wear resistant polymer, elastomer and/or natural or synthetic rubber or other materials capable of providing the desired functional characteristics. The outsole 38 also can be constructed to include thermoplastic elastomers and/or thermoset elastomers. Other materials such as fiber-reinforced polymers can be used. These can include epoxy, polyethylene, polyester, thermosetting plastic reinforced with carbon, glass, and/or aramid fibers.

Although the illustrated embodiment of the sole 14 includes the midsole 36 and the outsole 38, the present invention may be implemented in alternative embodiments with a sole 14 having only a midsole 36 or only an outsole 38. Other components such as a topsole (not shown) can be included. In any of these cases, the ground engaging surface 16 is defined by the portion of the sole 14 defining the bottom of the footwear 10. Generally, regardless of which components are present, the sole 14 can form the bottommost portion of the footwear 10.

The outsole 38 in the illustrated embodiment includes a base surface 40 from which one or more features or shapes project to provide a traction surface for the sole 14. The illustrated embodiment includes a plurality of guard lugs, several of which are designated 42, that project from the base surface 40 and define at least a portion of the ground-engaging surface 16. The base surface 40 may include other features or shapes that do not project to provide the ground-engaging surface 16 but rather provide other aesthetic or functional aspects, such as grooves for controlling flex of the outsole 38 during use or sipes to direct water, or both. The term “ground engaging surface” or “traction surface” refers to the ground contacting surface or surfaces of the sole 14 constructed to provide traction between the footwear 10 and an underlying ground surface.

The base surface 40, in one embodiment, includes one or more features, such as the projections designated 18, which can receive screws 20 to enhance the traction provided by the ground-engaging surface. The base surface 40, in one embodiment, also includes one or more features, such as the drain guides designated 24, indicating where the sole 14 can be drilled to enhance drainage. In one embodiment, the projections 18 and drain guides 24 are positioned in void spaces around the lugs 42.

The outsole 38 in the illustrated embodiment extends substantially the full length and width of the sole 14, with the base surface 40 extending through the forefoot section 30, arch or midfoot section 32 and heel section 34. The base surface 40 is generally bounded by a peripheral edge, including a medial edge 44, a lateral edge 46, a toe edge 48, and a heel edge 50.

The base surface 40 can be continuous over the outsole 38, i.e. the base surface 40 extends substantially the full length and width of the outsole 38, or discontinuous over the outsole 38, i.e. the base surface 40 extends less than the full length and/or width of the outsole. In the embodiment shown herein, the base surface 40 includes at least a forefoot portion or base 40A at the forefoot section 30 and a heel portion or base 40B at the heel section 34.

The guard lugs 42 can be discretely formed and distributed across the base surface 40 of the outsole 38. The number, size, shape, arrangement, and configuration of guard lugs 42 may vary from application to application. In the illustrated embodiment, multiple forefoot guard lugs 42A extend from the forefoot base 40A at the forefoot section 30 and multiple heel guard lugs 42B extend from the heel base 40B at the heel section 34. The midfoot section 32 can be substantially free of any guard lugs 42.

The guard lugs 42 are arranged to protrude downward from the base surface 40 to contact the ground or other surface during use. For example, the guard lugs 42 may be arranged so that a distal end 52 of the guard lugs 42 contacts the ground or other surface during use. Each of the guard lugs 42 includes a sidewall 54 that extends from the base surface 40 to the distal end 52 that contacts the underlying ground surface. In this embodiment, at least some of the guard lugs 42 are chevron- or V-shaped, with the sidewall 54 being chevron- or V-shaped when viewed from the bottom, as in FIG. 2, and may be referred to herein as chevron lugs.

Referring to FIG. 3, an enlarged view of the forefoot section 30 of the sole 14 is shown, including details of the forefoot chevron lugs 42A. The sidewall 54 of the chevron lugs 42A can include a first V-shaped surface 56 defining an outer vertex 58 and a second V-shaped surface 60 defining an inner vertex 62, with end surfaces 64, 66 joining the first and second V-shaped surfaces 56, 60. In the forefoot section 30, the outer vertex 58 of the guard lugs 42A can be directed toward the toe edge 48 of the outsole 38.

Referring to FIG. 4, an enlarged view of the heel section 34 of the sole 14 is shown, including details of the heel guard lugs 42B. The heel guard lugs 42B can be substantially similar to the forefoot guard lugs 42A described above with respect to FIG. 3, with the exception that the orientation of the chevron lugs 42B can be inverted in the heel section 34, with the outer vertex 58 of the lugs 42A directed toward the heel edge 50 of the outsole 38.

The guard lugs 42 can be arranged in any suitable pattern or groupings over the base surface 40 of the outsole 38. For instance, as best shown in FIG. 3, the forefoot guard lugs 42A can be distributed in longitudinally-extending rows of aligned lugs over the forefoot base 40A, optionally including a medial row 72M extending along the medial edge 44, a lateral row 72L extending along the lateral edge 46, and a center row 72C between the medial and lateral rows 72M, 72L. The rows 72M, 72L, 72C can extend along straight or curving paths, such as the medial row 72M generally following the curvature of the medial edge 44 and the lateral row 72L generally following the curvature of the lateral edge 46. The guard lugs 42A in each row 72M, 72L, 72C are aligned along the straight or curving path, i.e. with the outer vertex 58 of a first lug 42A being disposed behind the inner vertex 62 of a second lug 42A that is forwardly-adjacent to the first lug 42A. Other numbers and arrangements of lugs 42A in the forefoot region 30 are possible

Referring to FIG. 4, the heel guard lugs 42B can be distributed in longitudinally-extending rows of aligned lugs over the heel base 40B, optionally including a medial row 74M extending along the medial edge 44 and a lateral row 74L extending along the lateral edge 46. The guard lugs 42B in each row 74M, 74L are aligned one behind another, i.e. with the inner vertex 62 of a first lug 42B being disposed behind the outer vertex 58 of a second lug 42A that is forwardly-adjacent to the first lug 42B. Other numbers and arrangements of guard lugs 42B in the heel region 34 are possible.

The outsole 38 can also include lugs that do not have a chevron shape, but rather have another polygonal shape. The non-chevron lugs 76 can include one or more lugs having a shape such as kite, diamond square, rectangular, or triangular, among other possible polygonal shapes. In the embodiment shown in FIG. 2, kite-shaped lugs 76 are disposed on forward and rearward sides of the midfoot section 32. Other lug designs and/or patterns can be employed.

The outsole 38 may also include a plurality of peripheral lugs adjacent to the peripheral edge of the base surface 40, including a plurality of medial peripheral lugs 78M arranged along the medial edge 44 and a plurality of lateral peripheral lugs 78L arranged along the lateral edge 46. The peripheral lugs 78M, 78L can be chevron- or V-shaped in a similar manner as the chevron lugs 42, including that the peripheral lugs 78M, 78L in the heel section 34 are inverted with respect to the peripheral lugs 78M, 78L in the forefoot section 30. The peripheral lugs 78M, 78L can also comprise lugs that do not have a chevron shape, but rather have another polygonal shape, such as kite, diamond square, rectangular, or triangular, among other possible polygonal shapes. Optionally, the lateral peripheral lugs 78L can have a split or siping 80 to improve traction along the lateral edge 46.

Referring to FIG. 2, the raised projections 18 can be discretely formed and distributed across the base surface 40 of the outsole 38. The number, size, shape, arrangement, and configuration of projections 18 may vary from application to application. In the illustrated embodiment, multiple forefoot projections 18A extend from the forefoot base 40A at the forefoot section 30 and multiple heel projections 18B extend from the heel base 40B at the heel section 34. The midfoot section 32 can be free of any projections 18. The center of the outsole 38, generally defined along the length of the footwear between toe and heel, can be free of any projections 18.

The raised projections 18 may be arranged along the outsole 38 symmetrically or non-symmetrically about the center of the outsole 38, as desired. In the illustrated example, the projections 18 are non-symmetrical about the center of the outsole 38, with the projections 18 along the medial edge 44 of the outsole 38 being longitudinally offset from the projections 18 along the lateral edge 46 of the outsole 38, with respect to the longitudinal direction generally extending along the length of the footwear 20 between the toe edge 48 and heel edge 50. The medial and lateral projections 18 are also laterally offset from each other, with respect to the lateral direction generally extending across the width of the footwear 10 between the medial and lateral edges 44, 46.

The projections 18 are arranged to protrude downward from the base surface 40 a distance less than that of the guard lugs 42 to not contact the ground or other surface during use, as explained in further detail below. For example, the projections 18 may be arranged so that a distal end 82 thereof does not contact the ground or other surface during use. Each of the projections 18 includes a sidewall 84 that extends from the base surface 40 to the distal end 82. In this embodiment, at least some of the projections 18 are circular (or cylindrical), with the sidewall 84 being circular when viewed from the bottom, as in FIG. 2. Other non-limiting examples of shapes for the projections include, but are not limited to, hexagonal, square, or triangular, among other possible polygonal shapes. A circular or cylindrical shape may be preferred in combination with the chevron guard lugs 42 as a circular sidewall 84 allows the projections 18 to be nested closely with the chevron guard lugs 42. Further, it allows the projection 18 to correspond in shape with the screw head.

With reference to FIGS. 5-7, the distal end 82 of the projections 18 can include a screw-receiving surface 86 disposed inwardly of a peripheral edge 88, which joins the sidewall 84. The projections 18 are closed and non-threaded, i.e. to do not have a preexisting hole or preformed aperture, such as threaded bores, for receiving screws, spikes, or cleats. This allows the footwear 10 to be worn without any screws in the projections 18, and without getting debris and dirt getting into preformed holes. The screw-receiving surface 86 of the distal end 82 faces the underlying ground surface and are closed prior to installation of screw 20. Drilling a screw 20 into the screw-receiving surface 86 forms a blind hole in the sole 14.

The distal end 82 can curve upwardly from the peripheral edge 88, with the screw-receiving surface 86 being concave. In other embodiments, the screw-receiving surface 86 can be flat or planar. The projections 18 can approximate truncated cones or conical frustums, with the sidewall 84 slanting inwardly from the base 40 to the peripheral edge 88.

To convert the footwear 10 back, such as for dry or non-icy conditions, a user can remove screws 20. In cases where a screw 20 (FIG. 8) is installed in the projection 18 and subsequently removed, a hole is left in the distal end 82. The concave screw-receiving surface 86 and/or the slanted sidewall 84 place the center of the projection 18 under greater compression, which can help to close the hole left after removal of the screw 20. To further aid this, the material of the projections 18 can be resilient such that it will spring back or recover to at least some degree, which will help seal the hole. Examples of resilient materials for the projections 18, and optionally for the entire outsole 38, include rubber, synthetic rubber, polyurethane (PU), thermoplastic polyurethane elastomer (TPU), ethylene-vinyl acetate (EVA), nylon, or other polymer blends thereof.

The distal end 82 of the projections 18 optionally include a pilot hole 90 as a guide for the insertion of the screw 20. The pilot hole 90 can be pre-formed in the projection 18 for the user, such as by being molded with or drilled into the outsole 38 during production of the footwear 10. The pilot holes 90 can be located at the center of the distal end 82 to help center the screw 20 on the projection 18.

The distal end 82 may include an X-shaped formation 92, with the pilot hole 90 disposed at the center of the X-shaped formation 92, to help direct attention to the pilot hole 90 and to further help to center the screw 20 on the projection 18. The X-shaped formation 92 can be provided as an inwardly projecting feature on the distal end 82 as shown in the figures, or may be provided as a raised feature on the distal end 82.

The raised projections 18 can be arranged in any suitable pattern or groupings over the base surface 40 of the outsole 38. In the embodiment shown herein, the projections 18 are disposed between two the lugs 42, which can protect the projections 18 from wear. For instance, as best shown in FIG. 3, the forefoot projections 18A can be arranged in the medial row 72M of forefoot guard lugs 42A extending along the medial edge 44 of the outsole 38 and in the lateral row 72L of forefoot guard lugs 42A extending along the lateral edge 46 of the outsole 38. The projections 18A in each row 72M, 72L can be disposed between two of the forefoot guard lugs 42A, with the projections 18A aligned along the path defined by the row 72M, 72L, i.e. with the center of the projection 18A, shown by the optional pilot hole 90 in the figures, centered on the inner vertex 62 of the forwardly-adjacent lug 42A. The center row 72C of forefoot guard lugs 42A can be free of any projections 18A. Other numbers and arrangements of projections 18A in the forefoot region 30 are possible.

At least some of the projections 18A can be nested with the chevron-shaped guard lugs 42A. As shown herein, each of the plurality of raised projections 18A are nested in the second V-shaped surface 60 of one of the plurality of guard lugs 42A, with a line drawn between the ends of the second V-shaped surface 60 (i.e. the corners where the surface 60 meets the end surfaces 64, 66) intersecting the nested projection 18A. The guard lugs 42A can have a width defined between the end surfaces 64, 66, and the width can be greater than the diameter of the projections 18A for nesting the projections 18A. Nesting the projections 18A in the area behind the lugs 42A defined by the second V-shaped surface 60 can protect the projections 18A from wear when screws 20 are not installed on the projections 18A. Nesting also maximizes the number of projections 18A and lugs 42A that can fit on the sole 14.

Referring to FIG. 4, the heel projections 18B can be arranged in the medial row 74M of heel guard lugs 42B extending along the medial edge 44 of the outsole 38 and in the lateral row 74L of heel guard lugs 42B extending along the lateral edge 46 of the outsole 38. The projections 18B in each row 74M, 74L can be disposed between two of the heel guard lugs 42BA, with the projections 18B aligned along the path defined by the row 74M, 74L, i.e. with the center of the projection 18B, shown by the optional pilot hole 90 in the figures, centered on the outer vertex 58 of the forwardly-adjacent lug 42B and on the inner vertex 62 of the rearwardly-adjacent lug 42B. At least some of the projections 18B can be nested with the chevron-shaped guard lugs 42B, as described above. The center of the outsole 38 can be free of any projections 18B. Other numbers and arrangements of projections 18B in the heel region 34 are possible.

Referring to FIG. 8, one embodiment of the screw 20 is shown. The screw 20 includes a threaded shaft 96 and a head 98. The head 98 is shaped for engagement with a complementary shaped tool (not shown) such as a drill bit of a power drill or a screwdriver. The head 98 includes a surface 100 that meets the outer face of the screw-receiving projection 18 when fully screwed in. The surface 100 can be defined by a flange or shoulder where the head 98 meets the shaft 96. The threaded shaft 96 of the screw 20 can extend into the base surface 40 of the outsole 38; alternatively the threaded shaft 96 can extend just into the projection 18, or can extend farther into the outsole 38, including into the midsole 36 in some applications.

The screw 20 can be fabricated from any suitable material for use with the outsole 38. For example, suitable materials may include one or more of metals such as aluminum or steel; polymeric materials such as thermoplastic elastomers, thermoset polymers, elastomeric polymers, silicone polymers, or natural and synthetic rubbers; composite materials including polymers reinforced with carbon fiber and/or glass; and combinations thereof.

The screw 20 can have various head shapes and lengths. Some non-limiting examples of shapes for the head 98 include hex, square, fillister, round, or oval. In one example, the screw 20 is a standard #8 hex-head screw having a length of approximately 3/8 inch. In at least some embodiments, the screws 20 can be an off-the-shelf component, making the screws readily available and easily replaceable if lost. The illustrated screws are, for example, conventional sheet metal screws that are available at virtually all home improvement stores and hardware stores. These screws have generally standardized head dimensions, including height, thereby making it easy for a consumer to obtain screws suitable for use with the present invention.

Other types of screws 20 are possible. Alternatively, instead of screws 20, other suitable traction elements such as cleats, studs, spikes, rivets, or similar element configured to enhance traction for a wearer during icy conditions can be used.

FIGS. 9A-9B are sectional views taken through line V-V of FIG. 2. FIG. 9A shows one of the projections 18 prior to installation of a screw and FIG. 9B shows the projection 18 after installation of screw 20. The distal end 52 of the guard lugs 42 can comprise a ground-contacting surface. A height 102 of the lugs 42, defined as the distance between the base surface 40 of the outsole 38 and the distal end 52 of each lug 42, can be generally uniform across the outsole 38 or can vary across different portions of the outsole 38. A height 104 of the projection 18, defined as the distance between the base surface 40 of the outsole 38 and the screw-receiving surface 86 of the distal end 82 of each projection 18, can be generally uniform across the outsole 38 or can vary across different portions of the outsole 38. It is noted that while the height 104 of the projections 18 is discussed with respect to the screw-receiving surface 86 of the projections 18, the height 104 may also be defined in terms of another portion of the distal end 82, such as the peripheral edge 88 as indicated at 106, and that all discussions of the projection height can apply to the screw-receiving surface 86, the peripheral edge 88, or another portion of the distal end 82 unless otherwise noted.

When screw 20 is installed, as shown in FIG. 9B, the threaded shaft 96 is screwed through the screw-receiving surface 86 on the distal end 82 of the projection 18 until the surface 100 of the head 98 meets the distal end 82. Optionally, the tip of the threaded shaft 96 can be lined up with the pilot hole 90 prior to drilling. A power drill or a screwdriver can be used for installing the screw 20. The threaded shaft 96 of the screw 20 is shown as extending through the outsole 38 and into the midsole 36, although other configurations are possible.

The diameter of the projection 18 can substantially the same as or slightly larger than the diameter of the screw head 98. This can prevent the screw head 98 from overhanging the projection 18 and creating a space in which dirt and debris could be trapped between the screw 20 and outsole 38. In addition, if the screw 20 is not centered on the projection 18 when installed, a slightly larger diameter projection 18 may accommodate for the off-center placement of the screw 20.

The height 102 of the guard lugs 42 can be greater than the height 104 of the projections 18 so that when screws 20 are not attached, the lugs 42 provide a comfortable surface for running, walking, or other activities. When a screw 20 is attached to the screw-receiving surface 86, the height 104 of the projection 18 sets the height of the screw 20 with respect to the lugs 42 on the sole 14. The difference between the height 102 of the lugs 42 and the height 104 of the projections 18, generally indicated by distance 108, can be less than a height 110 of the screw head 98 so that when a screw 20 is received by the projection 18, the screw head 98 extends beyond the surrounding lugs 42. Preferably, the screw heads 98 can extend only a slight distance 112 beyond the height 102 of the surrounding lugs 42 so that the traction is still provided by the surrounding lugs 42 and the screws 20 do not feel like cleats that scratch the underlying ground surface.

Alternatively, the respective heights 102, 104 of the guard lugs 42 and projections 18 can be configured such that the distal end of the screw head 98 is flush with, or nearly flush with, the distal end 52 of the surrounding lugs 42. In yet another alternative embodiment, the respective heights 102, 104 of the lugs 42 and projections 18 can be configured such that the distal end of the screw head 98 is above the distal end 52 of the surrounding lugs 42, with the lugs 42 standing proud of the screw head 98.

Referring to FIG. 2, the drain guides 24 can be discretely formed and distributed across the base surface 40 of the outsole 38. The number, size, shape, arrangement, and configuration of drain guides 24 may vary from application to application. In the illustrated embodiment, multiple drain guides 24 extend from the forefoot base 40A at the forefoot section 30. The midfoot section 32 and the heel section 34 can be free of any drain guides 24.

The drain guides 24 may be arranged along the outsole 38 symmetrically or non-symmetrically about the center of the outsole 38, as desired. In the illustrated example, the drain guides 24 are non-symmetrical about the center of the outsole 38, with the drain guides 24 along the medial edge 44 of the outsole 38 being offset from the drain guides 24 along the lateral edge 46 of the outsole 38.

The drain guides 24 are arranged to protrude downward from the base surface 40 a distance less than that of the projections 18 and guard lugs 42 to not contact the ground or other surface during use, as explained in further detail below.

With reference to FIG. 3, the drain guides 24 includes a rim 114 that extends from the base surface 40. In this embodiment, at least some of the rims 114 are circular or ring-shaped when viewed from the bottom, as in FIG. 2. Other polygonal shapes for the rim 114 are possible. A circular shape may be preferred in combination with the chevron lugs 42 as a circular rim 114 allows the drain formations to be nested closely with the chevron lugs 42.

The drain guides 24 can include a drillable surface 116 disposed within the boundary of the rim 114. The drillable surface 116 can be flat or planar. In other embodiments, the drillable surface 116 can be curved.

Optionally, the drillable surface 116 of the drain guides 24 includes a pilot hole 118 as a guide for the locating the drill bit within the center of the drillable surface 116, which can be the center of a circle defined by the rim 114. The pilot hole 118 can be pre-formed the user, such as by being molded with or drilled into the outsole 38 during production of the footwear 10. The pilot holes 118 can be located at the center of the drillable surface 116 to help center the drill bit on the drain guides 24.

The drain guides 24 can be arranged in any suitable pattern or groupings over the base surface 40 of the outsole 38. In the embodiment shown herein, the drain guides 24 are disposed between two the guard lugs 42, which can protect the drain guides 24 from wear. For instance, as best shown in FIG. 3, the drain guides 24 can be arranged in the medial row 72M of forefoot lugs 42A extending along the medial edge 44 of the outsole 38, in the lateral row 72L of forefoot lugs 42A extending along the lateral edge 46 of the outsole 38, and in the center row 72X of forefoot lugs 42A extending along the center of the outsole 38. The drain guides 24 in each row 72M, 72L, 72C can be disposed between two of the forefoot lugs 42A, with the drain guides 24 aligned along the path defined by the row 72M, 72L, 72C i.e. with the center of the drain guides 24, shown by the optional pilot hole 118 in the figures, centered on the inner vertex 62 of the forwardly-adjacent lug 42A. In the medial and lateral rows 72M, 72L of lugs 42A, the drain guides 24 alternate with the screw-receiving projections 18. In the center row 72C, drain guides 24 are provided to the rear of each lug 42, with no projections 18 provided in the row 72C. Other numbers and arrangements of drain guides 24 in the forefoot region 30 are possible.

At least some of the drain guides 24 can be nested with the chevron-shaped guard lugs 42A. As shown herein, each of the drain guides 24 are nested in the second V-shaped surface 60 of one of the guard lugs 42A, with a line drawn between the ends of the second V-shaped surface 60 (i.e. the corners where the surface 60 meets the end surfaces 64, 66) intersecting the nested drain guide 24. The width of the guard lugs 42A can be greater than a diameter of the rim 114 for nesting the drain guides 24. Nesting the drain guides 24 in the area behind the lugs 42A defined by the second V-shaped surface 60 can protect the drain guides 24 from wear. Nesting also maximizes the number of drain guides 24 and lugs 42A that can fit on the sole 14. When accompanied by nested projections 18A, the surface area of the forefoot region 30 can be densely packed with projections 18A, drain guides 24, and lugs 42A.

Referring to FIG. 1A, to add drain holes 26 to the footwear 10, the user can place a piece of scrap wood or other barrier inside the void defined by the upper 12, and position it at the forefoot section 30. The scrap wood or other barrier provides a substrate to drill into and prevents the drilling tool, i.e. a drill bit of a power drill or a screwdriver, from going too far into the footwear 10 and, for example, damaging the upper 12. The drilling tool is lined up with one of the drain guides 24, optionally using the pilot hole 118, and a drain hole 26 is drilled through the drillable surface 116. Next, the user can manually clean any debris from the exterior and interior of the sole 14. Optionally, drilling can be repeated more than once for a given drain hole 26 to provide a cleaner edge on the drain hole 26. In one example, the drain guides 24 can be sized for a ¼″ (6.5 mm) drill bit.

The drain holes 26 extend through the sole 14, including through the midsole 36, outsole 38, and any other non-removable portions of the sole 14, such as through a topsole (not shown), as well as through any strobel board, lasting board or other upper closing component that might overlay the sole, to allow drainage from the void or chamber for receiving person's foot defined by the upper 12 through the sole 14. In embodiments of the footwear 10 where a footbed, insole, sockliner or other similar inner sole component is disposed in the interior of the upper 12, the footbed, insole, sockliner or other similar inner sole component is typically not drilled through, and the user may remove such component from the footwear 10 prior to drilling any drain holes 26 and reinstall the component thereafter. In some applications, it may be desirable to drill through the footbed, insole, sockliner or other similar inner sole component.

FIG. 11 is an enlarged plan view of a portion of the bottom side of the outsole 38 that includes indicial markings 22, 28. The indicial markings 22 associated with the projections 18 comprise indicia or shapes that can convey information, including a message or instructions related to the raised projections 18. Such a message or instructions can indicate to the user what size or type of screw 20 should be used, and/or where the screw 20 should be placed. Those indicia can include letters, numbers, symbols, other characters, or any combination thereof. In the example shown, the indicial markings 22 include arrows 22A pointing to the raised projection 18, first text 22B showing what length of screw 20 to use (e.g. “⅜ IN”), and second text 22C showing what type of screw 20 to use (e.g. “#8 hex head”). While only one projection 18 is shown as having associated indicial markings 22, in other embodiments, indicial markings 22 can be associated with more than one projection 18.

While shown on the base surface 40, in other embodiments, indicial markings 22 can be provided on one or more of the projections 18, such as on the distal end 82 or screw-receiving surface 86. It is also noted that the pilot holes 90 and the X-shaped formations 92 on the projections 18 can function as indicial markings as well, as the pilot holes 90 and X-shaped formations 92 convey information related to the projections 18, including where the screw 20 should be placed.

The indicial markings 28 associated with the drain guides 24 comprise indicia or shapes that can convey information, including a message or instructions related to the drain guides 24. Such a message or instructions can indicate to the user where the drain holes 26 should be placed and/or what size or type of drill bit should be used to form the drain holes 26. Those indicia can include letters, numbers, symbols, other characters, or any combination thereof. In the example shown, the indicial markings 28 associated with one of the drain guides 24 include first arrows 28A pointing to the drain guides 24, first text 28B showing what size drill bit to use in metric units (e.g. “6.5 mm”), and second text 28C showing what size drill bit to use in imperial units (e.g. “¼ IN”). Additional indicial markings 28 associated with another one of the drain guides 24 include second arrows 28D pointing to the drain guides 24, and third text 28E describing the purpose of the drain guides 24 (e.g. “drain holes”). While only two drain guides 24 are shown as having associated indicial markings 28, in other embodiments, indicial markings 22 can be associated with one drain guide 24 or with more than two drain guides 24.

While shown on the base surface 40 outside the drain guides 24, in other embodiments, indicial markings 28 can be provided on one or more of the drain guides 24, such as on the rim 114 or on the drillable surface 116. It is also noted that the pilot holes 118 on the drain guides 24 can function as indicial markings as well, as the pilot holes 118 convey information related to the drain guides 24, including where the drill bit should be placed to being drilling a drain hole.

The indicial markings 22, 28 can be provided as raised features on the base surface 40 of the outsole 38. The base surface 40 is a suitable portion of the outsole 38 on which to place the indicial markings 22, 28 since a person can conveniently see the markings by simply turning the footwear 10 upside down. In some embodiments, the raised indicial markings 22, 28 may have a height of 1 millimeter or less from the base surface 40, a height of 0.4 mm of less from the base surface 40, etc. The height is preferably less than the height of the surrounding projections 18 and guard lugs 42 for protection from wear, as the indicial markings 22, 28 are less likely to contact the ground or other underlying surface during normal wear. As such, the guard lugs 42 project farther from the base surface 40 than the indicial markings 22, 28. The indicial markings 22, 28 can be molded with the outsole 38 during production of the footwear 10. While shown as raised features, indicial markings 22, 28 can alternatively be inwardly projecting features on the base surface 40, or can otherwise by applied to the outsole 38.

Referring to FIG. 12, the bottom surface of the outsole 38 may also include a plurality of serrated lugs 120. The serrated lugs 120 help to further enhance the grip of the sole 14. The serrated lugs 120 are arranged to protrude downward to contact the ground or other surface during use. For example, the lugs 120 may be arranged so that a distal end 122 of the lugs 120 contacts the ground or other surface during use. In addition to the distal end 122, the serrated lugs 120 have an inclined surface 124 defining an undercut that permits the lugs 120 to compress against the base 40 when walking or running on hard, flat surfaces. The lugs 120 in the forefoot region 30 are inclined rearwardly and the lugs 120 in the heel region 34 are inclined forwardly.

Referring to FIG. 2, the serrated lugs 120 can be arranged in one or more longitudinally extending rows across the forefoot and/or heel regions 30, 34 of the outsole 38. As shown, in the forefoot region 30, the rows of serrated lugs 120 begin at the rearmost edge of the forefoot (i.e. adjacent the arch) and extend forwardly along gradual curves. In the heel region 34, the rows of serrated lugs 120 begin at the forwardmost edge of the heel (i.e. adjacent the arch) and extend rear along generally straight lines. The outsole 38 can include elongated grooves 126 in the forefoot base 40A and heel base 40B in which the serrated lugs 120 are provided.

The heel portion 34 of the outsole 38 can define a heel slot 128 that extends longitudinally through a center of the heel base 40B, between the rows of serrated lugs 120. The heel slot 128 may be configured to fit about a heel channel 130 of the midsole 36. In the forefoot region 30, the rows of serrated lugs 120 are separated by the center row 72C of forefoot lugs 42A.

The footwear 10 can be compatible for use with a gaiter (not shown) to prevent sand, dirt, rocks, and other debris from getting inside the footwear 10. Such gaiters often include a stirrup that runs underneath the footwear to keep the gaiter securely in place. In the illustrated embodiment, the outsole 38 defines a gaiter track 132 that extends across the midfoot section 32 of the sole 14. The gaiter track 132 extends laterally across the outsole 38 from the medial edge 44 to the lateral edge 46, substantially at the narrowest portion of the sole 12. In this application, the gaiter track 132 is configured to make it easier for the wearer to wear a gaiter having a stirrup that runs underneath the midfoot and wraps around the peripheral edges of the sole 14. The gaiter track 132 can be a substantially flat surface without any lugs, projections, tread, or other formations, which allows the gaiter stirrup to run smoothly over the outsole 38, away from the ground, which reduces wear on the stirrup. The size, shape, and configuration of the gaiter track 132 may vary from application to application. For example, the gaiter track 132 may be eliminated in some applications.

The various lugs 42, 76, 78, 120 of the illustrated embodiment are merely exemplary, and may be varied from application to application to adjust the characteristics of the sole 14. For example, the number, position, depth, width and cross-sectional shape of the lugs 42, 76, 78, 120 may be varied to tune the outsole 38. These variations may be used to provide global or localized variation in the gripping and traction characteristics of the sole 14.

There are several advantages of the present disclosure arising from the various features of the articles and methods described herein, which may be implemented alone or in combination in different applications. For example, the embodiments of the invention described herein provide screw-receiving projections with indicial markings on the sole for adding screws in predesignated locations to increase traction. By providing the projections in predesignated locations, accompanied by indicial markings conveying information regarding the type of threaded screw that can be received by the plurality of raised projections and where to attach a threaded screw to the sole, the user is clearly informed as to where screws may be added and how to properly install them. The dedicated screw-receiving projections, with optional pilot holes, gives the user confidence to add screws in a do-it-yourself approach without damaging the footwear. The various screw-receiving projections are spaced from each other in optimal locations for traction across the entire shoe. Without the screw-receiving projections and indicial markings, a user might insert screws too close together for an uncomfortable feel, or too far apart and not get the necessary traction. A user may also drill into a location on the sole that is not thick enough to support a screw. Further, the screw-receiving projections can be set at a height selected to function as secondary lugs when no screws are installed, while providing a somewhat flexible and resilient pedestals for any installed screws. Also, the height of the screw-receiving projections can be selected to locate standard machine screws (identified by indicia on the sole) at an appropriate height with respect to the remainder of the sole lugs or sole treads.

Another advantage of the present disclosure realized in at least some embodiments is that the footwear, and particularly the sole, is readily adaptable for all seasons, terrains, and conditions. For example, in icy conditions, screws can be added for increased traction and gripping. In dry conditions, the screws can be removed. In wet conditions, drain holes can be added for enhanced drainage.

Yet another advantage of the present disclosure realized in at least some embodiments of the articles and methods described herein is that the dedicated drain guides are provided on the sole for adding drain holes in predesignated locations to enhance drainage. By providing the drain guides in predesignated locations, accompanied by indicial markings conveying information such as where to drill drain holes on the sole for optimal drainage and what type of drill bit may be used, the user is clearly informed as to where drain holes may be added and how to properly drill them. The dedicated drain guides, with optional pilot holes, gives the user confidence to add drain holes in a do-it-yourself approach without damaging the footwear or interfering with the surrounding lugs. The various drain guides are spaced from each other in optimal locations for drainage across the forefoot of the footwear. Without the drain guides, a user might form drain holes too close together and weaken the sole.

The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z. 

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. An article of footwear comprising: an upper adapted to receive a foot; a sole joined with the upper and adapted to provide traction between the foot and an underlying ground surface, the sole comprising: a base surface; a plurality of guard lugs extending from the base surface, each of the plurality of guard lugs having a distal end forming at least a portion of a ground-engaging surface and a lug height defined by the distance between the base surface and the distal end; a plurality of raised projections capable of receiving threaded screws to increase the traction between the sole and the underlying ground surface, each of the plurality of raised projections extending from the base surface to a screw-receiving surface adapted to confront a screw head of the threaded screw and having a projection height defined by the distance between the base surface and the screw-receiving surface, the projection height being less than the lug height; and information-conveying indicial markings provided on at least one of the base surface and the plurality of raised projections, the indicial markings conveying information regarding at least one of the type of threaded screw that can be received by the plurality of raised projections and where to install a threaded screw in each of the plurality of projections.
 2. The article of footwear of claim 1, wherein the plurality of guard lugs project farther from the base surface than the indicial markings.
 3. The article of footwear of claim 1, wherein the indicial markings comprise shapes on the base surface comprising at least one of letters, numbers, and symbols.
 4. The article of footwear of claim 3 wherein the indicial markings comprise one or more raised elements molded on the base surface.
 5. The article of footwear of claim 3, comprising pilot holes on the screw-receiving surface of each of the plurality of raised projections.
 6. The article of footwear of claim 5, comprising X-shaped formations on the screw-receiving surface of each of the plurality of raised projections, with the pilot holes disposed at a center of each of the X-shaped formations.
 7. The article of footwear of claim 1, wherein the sole comprises a plurality of drain guides indicating where drain holes can be formed in the sole to enhance drainage.
 8. The article of footwear of claim 7, wherein the plurality of drain guides comprise a raised rim extending from the base surface and a drillable surface disposed within a boundary defined by the raised rim.
 9. The article of footwear of claim 7, wherein the sole comprises information-conveying indicial markings provided on the base surface and associated with the plurality of drain guides, the indicial markings conveying information regarding how to modify the sole for enhanced drainage.
 10. The article of footwear of claim 7, wherein: the sole comprises a forefoot region, an arch region, and a heel region; the plurality of guard lugs and the plurality of raised projections are disposed in the forefoot and heel regions; and the plurality of drain guides are disposed in the forefoot region.
 11. The article of footwear of claim 1, wherein the plurality of raised projections are non-threaded and the screw-receiving surfaces comprise closed ground-facing surfaces.
 12. The article of footwear of claim 1, comprising at least one screw having a threaded shaft and a head, the at least one screw receivable on one of the plurality of raised projections with the head of the screw meeting the screw-receiving surface of the one of the plurality of raised projections, wherein the at least one screw forms at least a portion of the ground-engaging surface when received on the one of the plurality of raised projections.
 13. The article of footwear of claim 1, wherein: the base surface is bounded by a peripheral edge comprising a medial edge, a lateral edge, a toe edge, and a heel edge; the plurality of raised projections comprise medial projections provided along the medial edge and lateral projections provided along the lateral edge; and the medial and lateral projections are longitudinally offset from each other with respect to a direction generally extending along the length of the footwear between the toe edge, and a heel edge.
 14. The article of footwear of claim 1, wherein the sole comprises an outsole and a midsole positioned between the upper and the outsole, the outsole comprising the base surface.
 15. The article of footwear of claim 1, wherein: the plurality of guard lugs are chevron-shaped and have a first V-shaped surface defining an outer vertex and a second V-shaped surface defining an inner vertex; and each of the plurality of raised projections are cylindrical and are nested in the second V-shaped surface of one of the plurality of guard lugs.
 16. A sole for an article of footwear comprising: a midsole; an outsole joined to the midsole, said outsole including a forefoot portion, an arch portion and a heel portion, the outsole comprising: a base surface; a plurality of guard lugs extending from the base surface, each of the plurality of guard lugs having a distal end forming at least a portion of a ground-engaging surface and a lug height defined by the distance between the base surface and the distal end; a plurality of raised projections capable of receiving a threaded screw to increase the traction between the sole and the underlying ground surface, each of the plurality of raised projections extending from the base to a screw-receiving surface adapted to confront a screw head of a threaded screw and having a projection height defined by the distance between the base surface and the screw-receiving surface, the projection height being less than the lug height; and information-conveying indicial markings provided on the base surface or the plurality of raised projections, the indicial markings conveying information regarding the type of threaded screw that can be received by the plurality of raised projections or where to attach a threaded screw to the sole.
 17. The sole of claim 16, wherein the indicial markings comprise one or more raised elements molded on the base surface, and the plurality of guard lugs project farther from the base surface than the one or more raised elements.
 18. The sole of claim 16, comprising a plurality of drain guides indicating where drain holes can be formed through the outsole and midsole to enhance drainage.
 19. The sole of claim 18, wherein the plurality of drain guides comprise a raised rim extending from the base surface and a drillable surface disposed within a boundary defined by the raised rim.
 20. The sole of claim 19, comprising information-conveying indicial markings provided on the base surface and associated with the plurality of drain guides, the indicial markings conveying information regarding how to modify the sole for enhanced drainage. 